It is known that in most liquid-based chemical assays, a sample to be tested must be metered out (a precise aliquot must be delivered) by appropriate means. Additionally, it has been found necessary to meter out diluent for mixing with the sample to achieve an appropriately diluted sample. The step of dilution is usually carried out prior to mixing the sample with the reagent. The reagent must also be metered in an appropriate manner suitable to be employed in a given reaction. The precision of the method of obtaining an aliquot sets the limit of precision of any subsequent analytical measurement. The obtaining of precise aliquot and its dilution are also necessary in order to provide for excess reagent with respect to the sample, and to reduce the effects of interferants.
Both the preparation of the necessary materials and all these steps are time-consuming and inconvenient. The invention seeks a simplified and improved way of obtaining aliquots and dilutions of the to-be-assayed material.